Lock Ring Hold Open Device for Frac Sleeve

A lock ring fits into a housing recess defined by a sliding member such as a sleeve. The lock ring is loosely fitted in the recess when the sleeve is in an initial position. The lock ring is preferably smooth on an outer dimension and has a beveled end. The beveled end engages an internal taper in the housing if a force is placed on the sliding sleeve to return it toward the original position. Preferably the shifting of the sleeve to a ports open position places the ratchet on the sleeve in alignment with the lock ring to hold the sliding sleeve locked in the open position.